We only know of our universe what we can observe. I do believe their could be multiple universes but I don't think they would be similar. It seems infeasible that everything that leads up to the formation of our universe and galaxy and solar system and planet and life on earth and societal formation would be exactly the same only slightly different.

Unless it is all a simulation. In which case you could have infinite versions of the simulation running at the same time to encompass every possible outcome for every atom.

Have you watched Dark Matter on Apple TV. You might find it interesting.